1. Field of Invention
The present invention relates to a ring type infrared heating device used in manufacturing process for corrugated cardboard, more particularly to a ring type infrared heating device using ring type infrared lamps as heating source for accelerating the preheating process and for easy control, easy maintenance purpose.
2. Related Art
Accompanying with increasing demand of goods packaging and transportation, demand for packaging material will be also increased. Typical packaging materials are plastic materials, as they are easy in manufacturing and convenient in acquiring raw materials. However, the reserve of raw materials has been decreased day after days and the price has been gradually increased, in addition environment pollution caused by massive usage of plastic materials has been becoming more and more serious. Therefore, it has been a common consensus in industries and consumers to switch into environmentally friendly and recyclable packaging materials.
As corrugated cardboard has environmentally friendly, recyclable properties and as it can be designed according to the shape of various objects to meet demand, the corrugated cardboard is widely used as packaging material for conventional various objects. Corrugated cardboard with stronger structural strength even can replace conventional wood material so as to enlarge its application range.
As the structural strength of the corrugated cardboard is enhanced by heat shaping, preheating should be firstly conducted for each paper raw material during shaping operation so as to facilitate the shaping operation. Referring to FIG. 1, the manufacturing apparatus 10 as shown in the figure mainly comprises a plurality of heating devices 101 which are connected separately to a bottom linerboard conveying device 102, a core-layer conveying device 103 and a surface-layer conveying device 104. Each of the heating devices 101 is communicated to a common furnace 11 in which steam generated therein is used as the heat source for each of the heating devices 101, so as to conduct heating treatment to the paper raw materials disposed on each of the heating devices 101. Next, forming, shaping, and conveying operations are further conducted separately on the paper raw materials after heating treatment by the bottom linerboard conveying device 102, the core-layer conveying device 103 and the surface-layer conveying device 104, and finally a corrugated cardboard is thus formed.
Referring to FIG. 2, the heating device 101 is a hollow tubular shape and the conventional furnace 11 using kerosene or gas as fuel generates steam after burning. The furnace 11 is connected to the heating device 101 in such a manner that the steam generated by the furnace 11 can be transferred to the interior of the heating device 101. In this manner, the surface of the heating device 101 can be heated up for subsequent operations by steam serving as the heating source. As the furnace 11 is a large-scale facility which needs a large space for set-up, and accordingly the set-up cost of the furnace 11 is high. Additionally, burning kerosene or gas increases not only the operating cost but also the misgiving of safety. Furthermore, as the heating device 101 has to accommodate the steam provided by the furnace 11, the heating device 11 itself must has a thickness enough to withstand the pressure produced by steam. It is easy to cause hazardous condition if the pressure is improperly controlled. Therefore, the heating device 101 is often made by thick and heavy material such as steel; this will lead to such disadvantages of the conventional heating device as high overall manufacturing cost, complicated structure, bulky overall volume, difficulty in temperature control, so as not to be conducive in assembly, replacement, and maintenance operations.
Referring to FIG. 3, the heating device 101 is tubular in shape with a big-area heating zone ‘a’ formed on its surface. After the interior of the heating device 101 is filled with steam, its surface can gradually reach working temperature so that the paper raw materials, after passing through the heating device 101, can be heated up to a temperature conducive to its shaping operation that is subsequent to the forming operation. In practical making of corrugated cardboard, the width of the paper raw material is often subjected to change according to specific demand of finished product. Taking this figure as an example, the width of the paper raw material 12 is far smaller than that of the heating zone ‘a’ and is approximately equal to that of the heating zone ‘a2’. This will result in idle state of the rest heating zones (a1, a3), that is to say, this indirectly lead to waste of energy.
In view of the abovementioned disadvantages, how to provide a corrugated cardboard manufacturing apparatus with light-weight, small volume, high safety, energy-saving, easiness in maintenance, labor hour and cost saving is a crucial issue in the relevant industries.